Inserting Characters into a string

Class string provides member functions for inserting characters into a string. Figure 18.8 demonstrates the string insert capabilities.

Figure 18.8. Demonstrating the string insert member functions.

(This item is displayed on pages 898 - 899 in the print version)

 1 // Fig. 18.8: Fig18_08.cpp
 2 // Demonstrating class string insert member functions.
 3 #include 
 4 using std::cout;
 5 using std::endl;
 6
 7 #include 
 8 using std::string;
 9
10 int main()
11 {
12 string string1( "beginning end" );
13 string string2( "middle " );
14 string string3( "12345678" );
15 string string4( "xx" );
16
17 cout << "Initial strings:
string1: " << string1
18 << "
string2: " << string2 << "
string3: " << string3
19 << "
string4: " << string4 << "

";
20
21 // insert "middle" at location 10 in string1
22 string1.insert( 10, string2 ); 
23
24 // insert "xx" at location 3 in string3 
25 string3.insert( 3, string4, 0, string::npos );
26
27 cout << "Strings after insert:
string1: " << string1
28 << "
string2: " << string2 << "
string3: " << string3
29 << "
string4: " << string4 << endl;
30 return 0;
31 } // end main

 

 Initial strings:
 string1: beginning end
 string2: middle
 string3: 12345678
 string4: xx

 Strings after insert:
 string1: beginning middle end
 string2: middle
 string3: 123xx45678
 string4: xx

 

The program declares, initializes and then outputs strings string1, string2, string3 and string4. Line 22 uses string member function insert to insert string2's content before element 10 of string1.

Line 25 uses insert to insert string4 before string3's element 3. The last two arguments specify the starting and last element of string4 that should be inserted. Using string::npos causes the entire string to be inserted.